Part a: the sun produces 3.9 ⋅ 1033 ergs of radiant energy per second. how many ergs of radiant energy does the sun produce in 2.45 ⋅ 105 seconds? express your answer in scientific notation and show your work. (5 points)

part b: which is the more reasonable measurement of the distance between the tracks on a dvd:
7.4 ⋅ 10−4 mm or 7.4 ⋅ 104 mm? justify your answer. (5 points)

Lems1. the following data set represents the scores on intelligence quotient(iq) examinations of 40 sixth-grade students at a particular school: 114, 122, 103, 118, 99, 105, 134, 125, 117, 106, 109, 104, 111, 127,133, 111, 117, 103, 120, 98, 100, 130, 141, 119, 128, 106, 109, 115,113, 121, 100, 130, 125, 117, 119, 113, 104, 108, 110, 102(a) present this data set in a frequency histogram.(b) which class interval contains the greatest number of data values? (c) is there a roughly equal number of data in each class interval? (d) does the histogram appear to be approximately symmetric? if so, about which interval is it approximately symmetric?

Tickets to a science exposition cost $5.75 each for studentd and $7.00 for adults. how many students and adults went if the ticket charge was $42.75

Kayla wants to find the width, ab, of a river. she walks along the edge of the river 65 ft and marks point c. then she walks 25 ft further and marks point d. she turns 90° and walks until her location, point a, and point c are collinear. she marks point e at this location, as shown. (a) can kayla conclude that δ and δ are similar? why or why not? (b) suppose de = 15 ft. what can kayla conclude about the width of the river?